package com.atguigu.day17.test06;

import java.util.Iterator;
import java.util.LinkedHashSet;
import java.util.Scanner;

/**
 * @author fenge
 */
public class Test06 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        String s = scanner.next();
        char[] chars = s.toCharArray();
        LinkedHashSet<Character> set = new LinkedHashSet<>();
        for (int i = 0; i < chars.length; i++) {
            set.add(chars[i]);
        }
        Iterator i = set.iterator();
        for (Character character : set) {
            System.out.print(character+"");
        }
    }
}
